Last month, the EPA denied a petition to remove stationary combustion turbines from the list of sources subject to regulation for emissions of air toxics, maintaining public health protections for communities near these facilities.

 

“The agency denied the joint petition filed in 2019 by groups including American Fuel & Petrochemical Manufacturers and the American Petroleum Institute who asked to delist combustion turbines from the National Emissions Standards for Hazardous [Air] Pollutants (NESHAP), which imposes curbs on emissions of known carcinogens like formaldehyde and benzene,” reports Reuters.

As a result of denying this petition, stationary combustion turbines will continue to be required to comply with national limits on hazardous air pollutants (HAPs) such as formaldehyde under Section 112 of the Clean Air Act (CAA).

“Today’s action will ensure people who live, work and play near these facilities are protected from harmful air pollution,” said EPA Administrator Michael S. Regan in an Agency news release. “EPA is committed to ensuring every community has clean air to breathe, especially those that have been overburdened and disproportionately impacted by poor air quality for too long.”

Stationary combustion turbines are typically located at power plants, compressor stations, landfills, and industrial facilities like chemical plants. These turbines generally operate using natural gas, distillate oil, landfill gas, jet fuel, or process gas. Toxic emissions are present in the exhaust gases of these turbines and are the result of combustion of the gaseous and liquid fuels.

“Around 250 U.S. gas turbines had been subject to the rule, according to an EPA list,” Reuters adds.

Section 112 regulations limit emissions of air toxics, or HAPs, such as formaldehyde, toluene, benzene, acetaldehyde, and metallic HAP (e.g., cadmium, chromium, manganese, lead, nickel). HAPs are known to cause—or are suspected to cause—cancer or other serious adverse health and environmental effects.  Formaldehyde and acetaldehyde are probable human carcinogens.

“Petitioners requested EPA remove, or ‘delist,’ combustion turbines, saying that cancer risks from this source category were below 1-in-1 million and would meet the statutory ‘delisting’ threshold,’” the Agency news release adds. “EPA has reviewed data and analyses submitted as part of this petition as well as additional emissions testing data. EPA is denying the petition based on the agency’s determination that the petition is incomplete and because EPA cannot conclude that there are adequate data to determine that the delisting thresholds in the [CAA] have been met. This is primarily due to both the uncertainty in the HAP emissions from affected sources and the missing emissions data from a large number of affected sources in the petitioners’ risk analysis.”

The EPA is currently seeking additional information from stakeholders on next steps for a broad-based approach to new and existing combustion turbines, including a proposed revision to the air toxics standards for combustion turbines, as well as separate rulemakings to address ozone-forming pollution from new combustion turbines and to establish greenhouse gas (GHG) emissions guidelines for existing combustion turbines.

For more information, see the EPA NESHAP website for stationary combustion turbines.